std_instead_of_core: avoid lint inside of proc-macro
- fixes https://github.com/rust-lang/rust-clippy/issues/10198
note: The lint for the reported `thiserror::Error` has been suppressed by [Don't lint unstable moves in std_instead_of_core](https://github.com/rust-lang/rust-clippy/pull/9545/files#diff-2cb8a24429cf9d9898de901450d640115503a10454d692dddc6a073a299fbb7eR29) because `thiserror::Error` internally implements `std::error::Error for (derived struct)`.
changelog: [`std_intead_of_core`]: avoid linting inside proc-macro
I confirmed this change fixes the problem:
<details>
<summary>test result without the change</summary>
```console
error: used import from `std` instead of `core`
--> tests/ui/std_instead_of_core.rs:65:14
|
LL | #[derive(ImplStructWithStdDisplay)]
| ^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: this error originates in the derive macro `ImplStructWithStdDisplay` (in Nightly builds, run with -Z macro-backtrace for more info)
```
</details>